Abstract
Abstract: :
Purpose: to investigate the vascularization of the choroidal melanomas by Color Doppler Imaging. Materials & Methods: In 10 patients with untreated choroidal melanomas and in 8 patients with choroidal melanoma 6 months after proton irradiation, Color Doppler examination has been performed. Mean thickness of the tumours at the examination was respectively 8.71 + 2.51 mm and 7.15 + 1.73 mm. A Color Doppler unit Logiq 500 Pro (GE Medical System, Milwaukee, WI, USA), with a 9 MHz linear probe has been used. In order to obtain the best detection of the flow, several scans of the tumours have been performed; Power Doppler was used for detecting the slower flows. The number of vessels in each tumour has been evaluated. The velocities of the arterial and venous flows have been measured, and for the firsts the Resistivity Index (RI) has been calculated. The examination has been repeated after the intravenous injection of an echo amplifier (Levovist ®, Schering AG, Berlin, Germany). Results: Vessels have been found in all untreated and in 7 of 8 treated melanomas. In the first group, a higher number of vessels have been detected (mean number respectively: 4.4 + 1.35 vs 1.75 + 1.04, t-test p=0.000); besides a correlation was seen between the tumour thickness and the number of vessels (p=0.007). Arteries were mainly found in the body of the tumour (mean: 3.1 + 1.73 in untreated vs 1.38 + 0.73 in treated); 4 untreated and 2 treated melanomas had a major vascular axis (central in 3 subjects, peripheral in 3). With Power Doppler in 3 cases were detected large vascular areas, due probably to many adjacent vessels; in 6 untreated and in 3 treated tumours some venous flows were found at the basis of the tumour. Treated tumours had greater RI values (0.74 + 0.09 vs 0.63 + 0.11, t-test p=0.039), but no significant difference was seen in systolic (SV) and diastolic (DV) velocities between two groups. Some vessels previously unseen were detected with echo amplifier, both in untreated and treated tumours (respectively +2.32 + 0.63 and +1.57 + 0.46). Compared to previous determinations, the flow velocities were increased (SV +19.9 + 7.12%, VD +32.8 + 8.31%), but no RI changes were found. Conclusions: Color Doppler allows evaluating the vascularization of the choroidal melanomas. Compared to the proton treated tumours, the untreated melanomas have a greater number of vessels (arteries in the body, venous flow at the basis of the tumour), with lower Resistivity Index. The echo amplifier allows detecting vessels previously unseen; it could be useful in the follow-up of the proton therapy.
Keywords: melanoma • blood supply • imaging methods (CT, FA, ICG, MRI, OCT, RTA, S